In cell networks base stations serve mobile or fixed user equipment. Every base station has a limited radio coverage area. Radio resources in the form of frequency spectrum are reutilised among the cells to optimise the capacity of communications offered by the network. However, within one cell radio resources are restricted and these resources need to be managed efficiently. Various management procedures of the resources radio can be implemented, according to the choice of the operator, at the cell level or in the infrastructure of the cell network to optimise the employment of the frequencies and minimise interference.
As mobile telephone networks become more heavily used, the optimum use of available spectrum becomes very important. Any delay in making or terminating wireless communications, any unnecessary signalling or the use of an excessively high transmission power level will reduce the capacity of the system. However, obtaining optimised settings under all operating conditions is difficult.
A further difficulty is the rapidly varying traffic load in the cells. Depending on the time of day and public facilities provided within a cell, e.g. an airport or a football ground, large changes in traffic can occur, e.g. arrival of an aeroplane and all passengers turn on their mobile phones on disembarking, many making a phone call or accessing phonemail, termination of a football match followed by a large amount of messaging, etc. Areas of a cell having a high communication activity may be called “hot spots”. One proposed solution to hot spot problems is to vary the charges in accordance with the loading on the cell, a) by charging high rates users are dissuaded from using the service or b) are prevented from doing so because their tariff agreement does not allow connection at the highest charging rates hich are imposed at high traffic levels.
EP 1090515 proposes a solution to some of the problems associated with adjusting network control parameters to changing situations. A scheme is proposed for selecting a value for a first radio resource management parameter by keeping a statistic of values measured on the radio channels of a quantity. A second parameter associated with the first parameter is adjusted so that a certain fraction, e.g. %, of the values in the statistic are above the selected value of the associated parameter. However, selecting the value of the associated parameter based on a value being representative of a certain fraction of measured values of a related quantity is not ideal for some of the wide variety of control parameters used in the management of a cellular network. In particular, depending on the occasion, a mobiles communicating from within hot spot might be have measured values at an percentage of the values in the statistic. Thus, the selection algorithm of EP 1090515 is not universally applicable and is in need of improvement.
Methods of determination of the location of mobile units have been known for some time. They may be grouped into cell based measurement techniques, cell ID techniques and global positioning techniques. The most accurate is the latter but requires that each mobile includes a GPS receiver. The least accurate is the cell ID method, but it involves the least effort as information as to the location of the mobile unit with respect to a location area or to a cell is required for paging purposes. Techniques based on measurements within the cell provide an intermediate accuracy, e.g. of one or more hundreds of metres, and are usually based on the measurement of delays of signals propagated within the cell. The delays from two or three known points can be reported then the location of the mobile unit may be obtained by triangulation methods. There are serious privacy concerns about recording accurate mobile unit location somewhere in the infrastructure without user agreement.